Magnetic change-over valve



sept. 9, 1952 w. R. Ecml MAGNETIC CHANGE-OVER VALVE Filed Dec. 18, 1950 INVENTOR.

W R EDDY F/G. 4. BY M W ATTORNEYS Patented Sept. 9, 1952 Parana f oFF-ICE Wiliamnutert Eaaynsaruesviue;roklaasigiir to'PhilljpsaPetroleum Company; a: corporation .ofY Delaware reclaim.

v .-11 '-"This invention v`'relates `.to'fa'dispensing system for high pressureluids Yand .includessai device ifor automatically changing Withdrawal :connections from one source-of -luid to another.l :Income aspect,A it relates' .tof a"ful ly automatic changeover device lfor Vthe ytransfer i'of WithdrawalY con-.- nections" fromone source of-.fhigh :pressuref gas: fto another Aupon :decrease inzpressure.- offthe'r'st source. In anothery laspectfit lrelatesa-.toatully automatic changeover grandxcylinder.Lindicating assembly for fthe.transferioflwithdrawalLconnections from one zsource` of La .high pressuregasrito another Auponfdecrease`.in pressure'ffromitheirst source with the indicationnf: Whichrsourceorgas f is depleted. y

In dspensingiuids v:under'pressure'.from `containers Ias`,f.for. example,'1liquefied.:ipetroleum gas, a-device iforl automaticallyf changingawithdrawal connections from-one container to. .anotherxis desirable'` to .insurezarrv uninterruptedfiowr oftthe duid.' l.l/'arious :semi-.automatic and fully .automatic changeover devices have :been proposed heretofore. The purpose toi-.myrinvention;is1to provide a :dispensingrfsystem including. :..a ".flly automatic -zz'changeover Vde'vice which Y:possesses several desirable :characteristicswhich .-will ..be realized :upon reading therfollovving;specication.

. Anbb'ject of,:myzinvention:isztolprovde-zanim proved :changeover device `;w l1icl1'is fully. :automatic` and: ofrsimpliedyldesigneand construction whilezbeing efcientszand positive infitsfoperation. A furtherY objectif offzmy; invention'istozziprovide ani automatic Vchangeover. adevice which is; .composed of a minimum number ofspartsand depends for its operationf.onldecreasaiin zpressure from one of the sourcesofsupply. Another oblect-of my invention' is tto:providek-a changeover 4idevce for yliqueed#petroleum1gasffdispensing systems Which-.Willfgive `visual indicationlastc:which of the two sources. of ga'sfislbeing-use'd. l Stillenfothenobject'of' my invention is:to\providea"fully automatic; changeover; device for liqueedfpetro- -leum gas dispensing systemswhichwill: give visual indica'tio'na-as'` to fvvhichiof-ftwo Vsources. :of I gasLis being used and for use in coniiunctionaiwiththe devicezto indicate visuallyiwhennneta'nk:is empty and; further, to indicate/.visually whch'tankiis empty. Many, 1 other objects zrA and advantagesv'of my' changeoverdevice-awill be'srealized'uponzreading the'.followingdisclosurewhich;takenfwitlthe attached tdrawing, forms r.anpartfzofithisnspeci# cation. v j

In :the idrawing; Figure lfisan elevationalzview, partly :in- .-sectiom: of.` my indicating and .chan-geover device. :Egureiz isLan endvievvofithe apparatus off Figure l1. 'Figure v3 is'falsectional view cfthe apparatus taken `on the line .3f-#3710i Figure 'Figurei shows, inpart, an LPGfdispensing system Vvvithmy Aautomatic `changeover 'andfindi-f eating device. "i

Referring. nown to -the drawing, Vvand:specifically to- Figures l, 2, 1 and 13,1v .the apparatusi includes :a main body member vI I. V'Ihisbodymemberghas alconduit :0fvarying diameter lpassi-ng'from one end to'the otheran'd'also containsaside conduit communicating fromV` the exterior. to about amid# point =of"-tlf-ie-mainV conduit. Varioussections of thefmain conduittdthe bodyrmemberl II 4have d'iierentdiameters. For example, beginninggat .therleft of Figure 3, the rst portionfof the -con- -duit .is of relatively-large diameter and is threaded toaccommodate the-threadedend ofthe nozzle tting I5. At the end of this threaded-section is ..a.plain,VIV smooth -section of .conduit :which is -adapte'deto .accommodatefa ringwasher SI1. The

neXt;section..ofthe.conduit is ofi-slightly smaller diameter .than those: heretofore mentionedf-but isvn' axial alignment.. therewith. The change .in .diameter Yfromthe llarger' diametersection which accommodates the zresilient Vwasher and that which accommodates-member:22 .f serves .as a vshouldersagainst.;vvlfiich..the` resilient washer vIl isi placed. ilzErom fthe. section dof conduitv which contains .thelzelementLZZ is a'conduit section 21a of relativelyzsmallr diameter` extending fartherv to theright andidownwar-d somewhat. i in .the righthandlfhalf cof-the body I I is Ya conduitv 21'b..which is justf 'exactlyilikex conduit? 21a in the :left-hand half.' of z the. body :fmember `I I. The two :small diameter;;;conduitfsections: 21a .andLSZ'IbL-meet-lat -the centerof ZthebOdymember I I 4and communicatewiththepassage'38 or outlet conduit. When vinf,.1.1s.e,:fthe noz'zlettings I 5 rand I Silead Atheigas fromfistoragercylinder conduitsfto the changeover vandfithe gasleaveslthe body member AI'Ifthrough fthe sideloutl'etipassa'ge 38 fror'n-Wh1`ch itfiscon- .ducted :through pressurere'ducin'g: apparatusg-etc., ftditheappliances...v ;.-.i 1 f i' "fzThel dischargegendsl of'theunoaalettingsUI 5 *andlIzIfzfaremade'Y inthe-iormcf valve seats-so that fthe resilient'.sealingxmembersf125 iandi', when "pressedzagainstrrthe -cv'alve :.seats, will? form.. eftec'- tivea seals; E'Elements; i122 fandi23fare zmagnetsxto '.whichi1the'resilient :sealing members 2 5 Landi-#2 6, respectively, a arer attached. r;These-l magnets are intended: toz'lforceithe.resilient membersZE and Ill Saagainstlthe respective .valveseatsof :the nozzle iittingsp-IS. and lztofsealzoff the'fflowLof-gasfrom af cylinder orstdopen'the; nozzleittings to thefflow To the underside of a .rotor member I3 are attached two magnets 24a and 24h in the manner illustrated. As illustrative of the arrangement of these magnets, for example, the inner end of the magnet 22 may be the north pole, accordingly the outer or adjacent end of the magnet 24a is a north pole. In other words, the magnets 22 and 24a are arranged with like polarities adjacent. The two magnets 23 and 24h are disposed relative to each other in the opposite manner. In other words, when handle I4 is rotated 180 the adjacent poles of magnets 22 and 24hare of unlike polarity so that they will attract each other and at the same time the adja-V cent poles of magnets 23 and 24a will repel keach other. If it is desired, the magnets 24a and 24h may be separate magnets as just described; or, if desired, they may be one large magnet with an opening in the center for installation around a spindle I2. These magnets 24d and 24h, whether one magnet or two magnets, are attached to the bottom of the rotor I3, and this entire assembly is tted around the spindle I2, as shown. A pair of lock nuts 36 or other means may be used for holding this rotor assembly in place. An indent assembly 33, as shown, is provided for making certain that the handle I4 and the rotor I3 will remain in a desired position.

The threaded outlet 3'! which contains passage 38 is a straight member as shown and is preferably attached to an outlet pipe l by means of an L' 31a so that the handle I4 of the rotor I3 will be moved in a vertical plane when the apparatus is in operation. This arrangement is desired so when the apparatus is installed in an outdoor location that rain or freezing will not interfere with the ease of rotation of the rotor member I3.

Tothe left of the resilient member or washer Il in the nozzle member I5 is provided an opening (Figure 1). This opening 29 is intended to provide fluid communication from the tube leading to the nozzle member I 5 to a circular section bounded by the nozzle member I5, the resilient washer I7, and the body member il.

In Figure l are shown webs 43 and 44. Web 43 contains a conduit I8 which leads from the circular space, mentioned above, and bounded by the nozzle member I5, the resilient washer I 'i and the body member II, to a point within the space or" the indicator housing member 3I. This indicator housing member is composed of two parts, the left-hand part identified by reference numeral 4I is cast as an integral part of the main body member II. A removable part of this indicator housing is identied by reference numeral 42. Assembled between these two auxiliary housing members 4I and 42 is a diaphragm 29. To either side of this diaphragm member 29 are attached some red indicators or flags 33 and 33a. To the auxiliary housing member 4I is xed a transparent Window 45 through which the red ag or indicator 33 may be seen. The transparent window 46 is provided in the removable section 42 of the auxiliary housing member 3l so that the indicator 33a may be seen. The lengths of the indicators 33 and 33a extending from the diaphragm 29 are intended to be such that when the diaphragm is in its central vor at rest position neither one of the ags can be seen. When a greater pressure is exerted on the righthand side of diaphragm 29, the diaphragm will be extended toward the left and the flag or indicator 33 may then be seen through the transparent Window 45. In like manner, when the diaphragm is extended to the right, the red flag or indicator 33a may then be seen through the transparent window 46. The drill hole 29 and the conduit I 8 are intended to communicate fluid pressure from the nozzle member I5 into the space on the left-hand side of the diaphragm 29. When a greater pressure is communicated through'this assembly of conduits the diaphragm is extended to the right and the indicator iiag 33a will be visible through the transparent window 48.

The nozzle member I5 is provided with an opening 2I in its sidewall, and web member 44 has a small diameter conduit I9 therethrough extending from the circular space bounded by the Wall of the nozzle member I8, the adjacent resilient washer Ila, and the body member II. This small diameter conduit I9 extends from the circular space just mentioned to a point within the unremovable section 4I of the auxiliary housing 3l The speciiic positioning of the components of this small diameter conduit I9 may best be seen in Figure 1. This conduit I9 terminates at point 4l as illustrated. When the diaphragm' 29 is positioned adjacent the surface of the auxiliary housing member 4I and the auxiliary housing member 42 placed against the diaphragm, the opening 4l which is the end of conduit I9 opens directly into one end of the conduit 28. In this manner, fluid pressure is communicated through conduits I9 and 2t into the space between the diaphragm 2d and the removable section 42. Thus, when greater uid pressure is communicated from the right-hand side of the body member II than from the lefthand side and through the nozzle fitting I6, conduit I9, and through conduit 23 to the point on the right-hand side of the-diaphragm 29, the indicator flag 33 is then moved to the left and may `be seen through` the transparent window 45. The utility of the indicator assembly may be` best visualized upon reference to Figure 4. Thus. when greater pressure comes from cylinder 52.v the indicator 33 extends into the transparent window 45 indicating that the left-hand cylinder is empty. In like manner, when the greater pressure is coming from cylinder 5I, this pressure is communicated through the nozzle member I5, opening'Z, and through conduit I8 tothe left-hand sideof the diaphragm 29, thereby causing the red ag or indicator 33a to become visible through the transparent Window IPSA and the iiag in the window 46 indicates cylinder 52 is empty. y

Referring to Figure 4, theinstallation of the changeover and indicator assembly of my invention may be seen. LPG storage tanks 5I and 52 are connected respectively by conduits 53 and 54 to the respective nozzle members i5 and I6; Connected to the-threaded L 31a. is a conduit 51 containing a check valve y53. This conduit 5l is attached to a pressure reducing regulator 59 which in turn is connectedto the gas main or conduit 69 which is intended to conduct the gas to its ultimate use.

In the operation of my apparatus, when high pressure gas from cylinder 5I is conducted through conduit 53 f and through the nozzle member I5, the gas.V passes through the valve seat 34 and around. the edges of the magnet element 22, conduit 27a and out the outlet conduit 38. When the high pressure gas originates from the cylinder 52 it flows through the conduit 54 to the vnozzle member I6 and thence through the valve 35' andaround the side of the magnet 23,

that the tlirou'ghi conduit 5 2lb, and thence lout -the `fsde conduit 38. Whenbo'th cylinders-5 I and52 contain'iliqui'd, the pressure ofthe vvapor vover'lthe liquidfisabout theY same. V-And thisequal pressure -f-rom the cylinders is communicated through thefjconduits'53'and=54 into the corresponding nozzles I5 and "-'I6. `VAccordingly, the pressure throughout the Y main conduit is' approximately the same--and is about-thatof the pressure over the liquidinllthecylinder. "Whenthe pressure is fe'q-ualizd 'throughout the v conduits 21a, lland lb-vandfthelhandle 'I 4 isl'positioned as indicated in Figures' 1-fand"3,'the north pole of the magnet 24a frepels'the'f north 4'pole' of the 'magneti' 22 and forces the resilient r-sealing Vmember '25 Yagainst the valve seatE 34 `and closes 'the cylinder I5I againstthefowfof gas. "Under thesesame' oonditions, lthe #south --pole 'of `the YmagnetZh attractsthe#adjacentV nor-'th -pole of thelmagn'et-'23 aridfremoves the resilient member *26 from Toontactfiwithfthe-valve-seat` and, accordingly, gas can-owfrom cylinder 52 through the nozzle'il and out the side delivery tube 38 lto lthe Jappliances fior .use. "The arrow "14'9 .pointsr to the outer-end of thef handle' I4 and accordingly-:indioatesthatvthe cylinderto the rightis the one trom `which-'gas is being withdrawn. Under these! conditions, pressure from Vthe cylinder52 isfco'mmunicated through the -conduit54, 'openthe diaphragmZS. v-Thus. pressure onthelr'i'ghthand Yside of this `diaphragm tends -to ymove the diaphragm v'from rightto-ileft. This diaphragm will'move'fin'lthis directiononlyif there isa suicient-pressure differential. This pressure differential-will exist onlyund'er the conditionswhen thetank 5I is empty-or hasbeen removed `from the `line for1 replacement. Howeven when the tank-5 I viis fullor contains' at least some liqueed gas, the pressure from :this liquid .is communicated-throughthe conduit 53` into nozzle I5 and thencevthrough the'opening-"ZII, conduit I8a'nd to the left-hand side ofthe diaphragmr29. This pressure then tends tovmove the diaphragmlfrom the r left'to ther'ight. '.'Thus pressures from both cylinders 5I and 52 lare equal,. and, of course, thereis-no movementof the diaphragm-29 and neither-oftheiags 33y or v33a can beseen. 'I-Iowever, -when `pressure in the. storage tank'52 "diminishes suiiiciently, the flag 33a. becomes visible through the lright-hand window-wand the red agfvisible through thiswindow indicates that the pressure on the cylinder 52 .hasrbeen v.decreased. Andlunder -this pressure decrease the tank 52 -is indicated as empty `or. substantially empty -a'nd needs replacement.

Whenthe contents of tank 52 have been withzdrawnuntil no liquidremains in .thetanlg a l'substantial drop in pressure results .and the greater' pressure in tank 5I yovercomes the magnetic forcevactingonvalve member25, moving the' latter'away'from-seat 34. The iiow of gas `rthrough'seat 34 results in a pressure drop of sufcient magnitude to overcome the magnetic force ur`ging-valve`25 closed,-so long as gasr is with'- "drawnfvia lline-ISEL The appearance of the nag "33l1'inwindow-` 45, indicating depletion of the 'contents cf"tank-52,"signals the operator or householder that lthis tank needs'to be'V removed 'and replaced, lHe' should first turn 'handle VI4 so `thatarrow M'points toward tank 5I,"toindicate "thatthat 'tankis now' on supply VThis reverses thepo'sition of 'themagn'ets causing valve; 25 to 'be held open'by magnet2'4b`and valve 25V to' be 'cl'osedby'magnet 24a. However, should the operatar remove-tank 52 before reversingvfehandlel no -harm will be done vfbecausefthe vpressure' fdro'p across valve-seat 35 is more thanlenough-toiovercome lthe-magnetic attraction'. between Imagnets 23and\ 24h, and hence-valve 26 will immediately close, thus acting in themanner cfa slugfche'ck valve. I 'Y When "the Itank 'has been replacedf 'by/ a-f'ffll tank, and "this full -tank :opened to-the' lindicator and` changeover assembly, high 'pressure-will' be communicatdthrough -the conduitd, l through opening "2I, *through conduits I9 and'fZSHto the right-hand-'side of' the. diaphragm 29. l-I-I-ighpressure on this side of the diaphragm will move' the diaphragm` -at least-to the. centralposition and the indicator'iiag will disappear from the 'dwindow- 46. :Under these conditions, the pressures on both'sides ofthe diaphragm 29 are abouti the same and -theindicatorf flag-will not v--be visible through eitherof the1windows'45for46.

In a similar mannerffwhen thetank 5| Ihasbecome depleted `of its liquid content, nofmoregas can then flow vthrough the valve 184 and f high pressure gas willthen come from tank 52-thro'ugh the valve 35 andwill open this -fvalvefsuf'ciently against the eiect ofthe fmagnet '23 .to permit fulluse of Vthevgas from. thetankf352. 'Thisfhigh pressure gas" in the conduit "2lb and.2 la will force the magnet 22Lto close the valve34against.`ithe attractive force of unlil:ef..poles"offthe magnets V`22Ib..an ;l 22. .Thelow pressure .from thef empty tank 5I .willthen be communicated'fthroughfithe opening 28; through. theconduit I 8 into the'spa'ce on "the left-hand'4 side of :the 'diaphragm T29 and .the diaphragm will be!:displaced"toward` `th'eleit,

whichmovement places 'the 'indi'catorlflag 33`in thefrwindow15. .Since 'the `indicator v"iiagi may' be seen through the windowf"45; the indicationais that the tank 5Iv semptyand needsxrepl-a'cing. When tank 5I has been'replacedbya'fullrtank, highpressure is 'then communicated throughfthis assembly. of conduits intothe space-'on the" lefthandside ofthe diaphragm 291and `this diaphragm will be again moved to its neutral position and the flag will disappear from the'window 45 indicating that both tanks'f5 Iv `and-"52 Dcontain liqueed petroleum rgas athighl pressures. 1

The construction of my changeover and indicator assembly lis vrelatively simple since 'three die `casting parts'are allthat are vnecessaryr the construction of'a completeunit. Themain body member I I is one of the cast elements, the removable section t2 of the indicatorr housing is a second element,v and the handle androtor` assembly, 'IIIr and I3, isthe third'of the Hcast .elements. The nozzle fittings' I5 4and I5 are standard elements and may be constructedin any manner desired. The magnets 24a and`24b: may, if desired, be a singlemagnet. 'In this case,'an opening should be provided in thec'enterthereof for installation Vof the rotor assembly on the spindle I2. However, operation is equallye'fcient when magnets Morand 24o are separate or individual magnets. The magnets' 22 and 23 are sufficiently smaller in diameter than the conduits in which `these magnets aredispos'ed so that the gaseous material will be relatively unobstructed in its ilow around these magnets. The resilient washers I1 and I '11a are of such material and construction and are so positionedV in the body member II that gas can easily now around these elements in either direction. Small vdiameter sections 27 and 21a and the small diamstruction of elements of this nature.

castings by drilling is standard practice in con- By maintaining the overall length of the main body member Yl l as short as possible will facilitate the drilling of these small diameter conduits. Unwanted conduits made when drilling wanted conduits may be threaded and sealed with threaded plugs. VSuch,construction is standard practice and is well known by those skilled in the art. `The changeover and indicator assembly, herein described, is given merely as an example and the apparatus of my invention should not be limited thereby but only by the following claims.

, I claim: v Y

l. In a Vliquefied gas system, an automatic changeover valve mechanism comprising, in cornbination, a body member provided with an inlet port for each of two supply sources, a common outlet port, a conduit connecting each of said inlet ports with said common outlet port, each o said inlet ports terminating as a valve seat, a free floating valve sealing member adjacent each valve seat, each valve sealing member being so positioned as toA close an inlet port when the forceiapplled to the sealing member in the direction of closure is greater than the force applied in the opposite direction, and a magnet for'supplylng an increment of force to said valve sealing memberto urge said sealing'rnember against its seat in a closed position.

2. In a liquefied gas system, an automatic changeover valve mechanism comprising, in combination, a body member provided with an inlet port for each of two sources of supply, a common outlet port, a conduit connecting each of said n inlet ports with said common outlet-port, each of said inlet ports terminating Ywithin said mechanism as a valve seat, a free oating valve sealing member adjacent each valve seat, said each free floating valve sealing member comprising a resilient sealing element and a permanent magnet, said each free iloating valve sealing member being so positioned as to close an inlet port when the force applied to the sealing member in the direction of closure is greater than the force applied in the opposite direction, and a magnetic means to supply at leasta portion of the closing force.

3. In a liquefied gas system, an automatic changeover valve mechanism comprising, in oombination, a body member provided with an inlet port for each oi two sources of supply, a common outlet port, a conduit connecting each invlet port with said common outlet port, each of said inlet ports terminating within said inechi;

anism as a valve seat, a free heating valve sealing mem-ber adjacent each valve seat, said each free floating valve sealing member comprising a resilient sealing element and a permanent magnet, said each tree floating valve sealing mem- -ber being so positioned in one each of said conduits as toeloseY an inlet port when the force applied to the sealing member in the direction of closure is greater than the torce applied in the opposite direction, a magnetic means tc supply at least a portion of the valve closing torce, said magnetic means comprising a rotatable permanent magnet disposed outside of said body member.

4i. In a lioueed gas system, an automatic changeover indicating valve mechanism comprising, lin combination, a body member provided with a first conduit extending longitudinally therethrough, a second conduit leading from the exterior of said body member to a midpoint 8 Y longitudinally of said first conduit, a thirdv conduit in said body member extending from a point near one end of said first conduit to a point in an auxiliary housing disposed at one side of said body member and at a midpoint longitudinally of said body member, a fourth conduitin said body member extending from a point near the other end of said irst conduit to a point in said auxiliary housing, a pressure responsive diaphragm Yin said auxiliary4 housing between the points of communication of said third andfourth conduitsv and said auxiliary housing, indicating means in communication with said diaphragm to indicate its position; a nozzle means threaded into each end oi said rst conduit in said-body member thereby forming valve seats, anfauxih lary opening in said nozzle members, a resilient ring member disposed between each of said nozzle means and said first conduit and forming fluid tight seals therebetween, said auxiliary openings, the spaces bounded by said resilient ring mem- Ibers, said nozzle means and the inner wall of said first conduit in said body member and said third andfourth conduits forming passages from said nozzle means to points in said auxiliary housing on either side of said diaphragm; a free floating valve sealing member adjacent each valve seat, said each free floating valve sealing member comprising a resilientsealing element and a permanent magnet, said each free, floating valve sealing member being sc positioneddn said first conduit in said body member as to form a seal between said resilient sealing elements and said nozzle means when the force applied to said sealing members in the direction of Aclosure is greater than the force applied infthe opposite direction, like poles of said permanent magnets being disposed adjacent said resilient sealing elements, a magnetic means to supply'at least a portion of the valve closing force, said magnetic means vcomprising a rotatable` permanent magnet disposed Ibetween the aforementioned permanent magnets.

5. In the system of claim 4 wherein said rotatable permanent magnet is disposed outside of said body member ,and` one end of which is adapted to attract an adjacent end oi one of the rst mentioned magnets, and to repel the adjacent end of the other of the :first mentioned magnets.

6. In the system of claim 5, indicating means to indicate the pair of magnet ends mutually attracting each other. l

7. In a system for dispensing liqueed gas consisting of two containers for the liquefied gas, a delivery line from each container, a check valve in an outlet line, said outlet line being in fluid communication with a pressure reducing valve and said pressure reducing valve on its outlet side being connected with a line for delivering gas to appliances, and an automatic indicating changeover valve assembly connected withy said two gas delivery lines and with said outlet line communicating with `said pressure reducing valve, said automatic changeover valve comprising, in combination, a body member provided with a first conduit extending longitudinally therethrough, a second conduit leading from the exterior of said body member to a midpoint longitudinally of said rst conduit member, said second conduit connected with said outlet line containing said check valve, a third conduit in said body member extendingfrom a point near one end of said first conduit to a point in an auxiliary housing disposed at one side of said body member and at a midpoint longitudinally of said body member, a fourth conduit in said body member extending from a point near the other end of said first conduit to a point in said auxiliary housing, a pressure responsive diaphragm in said auxiliary housing between the points of communication of said third and fourth conduits and said auxiliary housing indicating means in communication with said diaphragm to indicate its position; a nozzle means threaded into each end of said iirst conduit in said -body member thereby forming valve seats, one each of the other ends of said nozzle means being connected with one each of said gas delivery lines, an auxiliary opening in said nozzle members, a resilient ring member disposed between each of said nozzle means and said rst conduit and forming fluid tight seals therebetween, said auxiliary openings, the spaces bounded by said resilient ring members, said nozzle means and the inner Wall of said first conduit in said body member and said third and fourth conduits forming passages from said nozzle means to points in said auxiliary housing on either side of said diaphragm; a free floating valve sealing member adjacent each Valve seat. said each free oating Valve sealing member comprising a resilient sealing element and a permanent magnet,V said each free floating valve sealing member being so positioned in said rst conduit in said body memiber as to form a seal between said resilient sealing elements and said nozzle means when the force applied to said sealing members in the direction of closure is greater than the force applied in the opposite direction, like poles of said permanent magnets being disposed adjacent said resilient sealing elements, a magnetic means to supply at least a portion of the valve closing force, said magnetic means comprising a rotatable permanent magnet disposed between the aforementioned permanent magnets.

WILLIAM ROBERT EDDY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,138,988 Thomas Dec. 6, 1938 2,354,286 Whaley July 25, 1944 2,391,043 St. Clair Dec. 18, 1945 2,405,127 Beach Aug. 6, 1946 

